The Surfbird is a medium-sized coastal bird that appears in September in the Pacific Coast of Costa Rica, as they migrate towards the south to escape from winter. They are mainly grayish-brown on the upperparts, throat and chest, white with some dark spots on the underparts, bright yellow legs and a relatively small black bill with a little yellow on the base. Its color pattern helps them camouflage easily among the dark shore rocks.
The Ruddy Turnstone is one of the most conspicuous migratory coastal birds that pass through the Pacific coast of Costa Rica. Their plumage is fairly colorful, with white underparts, orange legs, wings that are patched in orange and black, black throat and gray head with black markings. This is true of breeding adult males, but also of females and juveniles, although with streaked face and throat instead of black. Juveniles are duller, but not easily confused with other sandpiper species, as they are generally bigger and their body shape is different.
The Lesser Yellowlegs is a coastal bird, very similar to the Greater Yellowlegs, albeit smaller as one would expect. Telling one apart from the other is difficult, as the size difference may not be apparent if both species are not close by. Both have long, bright yellow legs, with white underparts and mottled gray upperparts, which turn brownish during the non-breeding season. The bill is long and slender, mostly black, although non-breeding adults may show a very small basal portion that’s colored in yellow.
The Whimbrel is a mid-sized coastal bird with a relatively down curved, long bill. Its body is grayish brown with a mottled appearance, where some of the subspecies having a white back and rump. Its call is a high-pitched whistle. They appear very similar to the Curlews, however those species are much larger in comparison. They forage in the shallow waters along the coast, grabbing small invertebrates and crabs from the surface.
Most Sandpiper species are pretty similar, specially as they come to Costa Rica in non-breeding plumage. Having a few different species mixed up in a single group can help for identification, as some of them will be showing the breeding plumage that distinguishes them, as well as other features like leg color. In this case, the Least Sandpiper has yellow legs, distinguishing it from the very similar Semipalmated Sandpiper. Also this bird is similar to the Pectoral Sandpiper, however the Pectoral is a lot bigger, has a yellowish bill, and the breast is streaked and delineated vs the white belly.